97716-58-0Relevant academic research and scientific papers
Adducts of Schiff bases with tris(β-diketonato)lanthanide(III) complexes: Structure and liquid-crystalline behaviour
Binnemans, Koen,Lodewyckx, Katleen,Parac-Vogt, Tatjana N.,Van Deun, Rik,Goderis, Bart,Tinant, Bernard,Van Hecke, Kristof,Van Meervelt, Luc
, p. 3028 - 3033 (2003)
Adducts of the Schiff base 2-hydroxy-N-octadecyloxy-4-tetradecyloxybenzaldimine with tris(β dibenzoylmethanato)-lanthanide(III) complexes are described. The stoichiometry of the complexes is [Ln(dbm)3Lx], where Ln is a trivalent lant
The influence of molecular flexibility on the mesogenic behavior of a new homologous series based on azo-azomethine: Synthesis, characterization, photoisomerization and DFT study
Jadeja, Rajendrasinh N.,Katariya, Kanubhai D.,Nakum, Kiran J.,Savani, Chirag J.
, (2021/10/05)
Through condensation of 2-hydroxy-4-n-alkoxybenzaldehyde (n = 2 to 8, 10, 12, 14, 16, 18) with (E)-4-((2,4-dimethylphenyl)diazenyl) benzene-1,3-diamine, new homologous series of rod shaped calamite liquid crystals based on azo-azomethine have been prepared. All synthesized compounds were characterized by FT-IR, 1H NMR, and 13C NMR spectroscopy. Use Differential Scanning Calorimeter (DSC) and Polarizing Optical Microscope (POM) to check the liquid crystal properties of all synthetic compounds. In the homologous series, all the compounds are mesogenic; some of them are in the nematic phase; some of them appear in the smectic A phase, and some appear in the nematic and smectic A phases. UV–vis pectroscopy was used to study the photoisomerization in chloroform. DFT (Density functional theory) level calculations and complete geometric optimization of all synthetic compounds are performed using B3LYP/6-31+G (d, p) basis sets.
Synthesis, characterization, and mesomorphic properties of some new Schiff base homologues series and their Cu(II) complexes
Nakum, Kiran J.,Katariya, Kanubhai D.,Jadeja, Rajendrasinh N.
, p. 1 - 13 (2021/02/02)
In present study, we have synthesized two homologous series of some new Schiff base of 4-n-alkoxy-2-hydroxy benzaldehyde (n = 2–8, 10, 12, 14, 16, 18) with 4-amino acetanilide and their corresponding Cu(II) complexes. A series of new Schiff base containing two aromatic rings have been synthesized and characterized by various spectroanalytical techniques including FT-IR and 1H NMR. The mesomorphic properties of these compounds were observed by optical polarized light microscopy (POM) and confirmed by differential scanning calorimetry (DSC) study. It has been observed that all the newly synthesized compounds exhibit wide range SmA phase.
Polarization effect in luminescent mesogenic BF2 complexes derived from heterocyclic benzothiazoles
Hsu, Yuan?Chun,Wang, Chun?Yang,Hsiao, Pei?Chi,Cai, Yi-Hong,Lee, Gene?Hsiang,Lai, Chung K.
, (2019/12/09)
Two series of benzo(thia)xazoles 1–2 and one series of boron difluoride complexes 2-BF2 derived from benzothiazoles 2 were reported, and their mesomorphic and optical properties were investigated. The crystal and molecular structures of compound 2 and 2-BF2 (all n = 8) were determined by means of X?ray structural analysis, and both crystallize in the triclinic P-1 and monoclinic P21/c. The geometry at boron center is perfectly tetrahedral, and the overall molecular shapes are considered as rod?shape. Both benzo(thia)xazoles 1 and 2 exhibited N or/and SmC phase, and boron complexes 2-BF2 formed N or/and SmC phase. Benzothiazoles 2 showed a much wider temperature range of mesophase than those of benzoxazoles 1, which were attributed to the better polarization by sulfur atom incorporated. Boron complexes 2-BF2 (n = 10, 12) emitted a yellow?to?green emission at λmax = 569–571 nm in CH2Cl2. This is the first mesogenic BF2 complexes derived from benzothiazoles.
Chiral Bent-Shaped Molecules Exhibiting Unusually Wide Range of Blue Liquid-Crystalline Phases and Multistimuli-Responsive Behavior
Punjani, Vidhika,Mohiuddin, Golam,Kaur, Supreet,Choudhury, Angshuman Roy,Paladugu, Sathyanarayana,Dhara, Surajit,Ghosh, Sharmistha,Pal, Santanu Kumar
supporting information, p. 5859 - 5871 (2020/04/28)
Recently, an unprecedented observation of polar order, thermochromic behavior, and exotic mesophases in new chiral, bent-shaped systems with a ?CH3 moiety placed at the transverse position of the central core was reported. Herein, a homologous series of compounds with even-numbered carbon chains from n=4 to 18 were synthesized, in which ?Cl was substituted for ?CH3 at the kink position and a drastic modification in the phase structure of the bent-shaped molecule was observed. An unusual stabilization of the cubic blue phase (BP) over a wide range of 16.4 °C has been witnessed. Two homologues in this series (1-12 and 1-14) exhibit an interesting phase sequence consisting of BPI/II, chiral nematic, twist grain boundary, smectic A, and smectic X (SmX) phases. The higher homologues (1-16 and 1-18) stabilize the SmX phase enantiotropically over the entire temperature range. Crystal structure analysis confirmed the bent molecular architecture, with a bent angle of 148°, and revealed the presence of two different molecular conformations in an asymmetric unit of compound 1-4. A DFT study corroborated that the ?Cl moiety at the central core of the molecule led to an increase in the dipole moment along the transverse direction, which, in turn, facilitated the unusual stabilization of frustrated structures. Crystal polymorphism has been evidenced in three homologues (1-10, 1-12, and 1-14) of the series. On the application of mechanical pressure through grinding, compound 1-10 transformed from a bright yellow crystalline solid to a dark orange–green amorphous solid, which reversed upon dropwise addition of dichloromethane, indicating reversible mechanochromism in this class of compounds. In addition, excellent thermochromic behavior has been observed for compound 1-10 with a controlled temperature–color combination.
Schiff base of 4-n-alkoxy-2-hydroxy benzaldehyde with 4-amino acetophenone and their Cu(II) complexes: synthesis, characterization and mesomorphic behavior
Nakum, Kiran J.,Katariya, Kanubhai D.,Jadeja,Prajapati
, p. 1 - 13 (2019/12/12)
New homologous series of Schiff’s base of 4-n-Alkoxy-2-hydroxy benzaldehyde (n = 2 to 8, 10, 12, 14, 16, 18) with 4-amino acetophenone and their Cu(II) metal complexes have been synthesized. The compounds were characterized using various spectroscopic techniques including FT-IR, 1H-NMR, 13C-NMR. Mesomorphic properties of these compounds have been investigated with polarizing optical microscope and differential scanning calorimeter. These compounds exhibit wide range SmA phase as confirmed by their typical optical texture under polarizing microscope.
Luminescent mesogenic borondifluoride complexes with the Schiff bases containing salicylideneamines and β-enaminoketones core systems
Lei, Zih-Yang,Lee, Gene-Hsiang,Lai, Chung K.
, p. 44 - 56 (2018/04/02)
Three new families of borondifluoride complexes 1a–c derived from salicylideneamines 2a and β-enaminoketonates 2b–c were reported, and their mesomorphic and optical properties were also investigated. One single crystal and molecular structure of nonmesogenic BF2 complex 1c (n = 10) was resolved and the geometry of the central boron atom was tetrahedron. A larger dihedral angle of 81.3° between the two phenyl rings observed in crystal lattice was attributed to the lack of liquid crystallinity. Boron complexes 1a formed monotropic SmA phases, while boron complexes 1b exhibited enantiotropic SmC mesophases. The optical property of the boron complexes was dependent on their molecular structures, and they emitted a blue–to–green emission at λmax = 476–541 nm in the solution and 488–550 nm in the solid state. This is the first group of mesogenic BF2 complexes with the Schiff bases derived from respective salicylideneamines and β-enaminoketones.
Mesomorphic and DFT studies of terminal ester containing salicylaldimines and their copper (II) complexes
Singh, Hemant Kumar,Singh, Sachin Kumar,Kumar, Vijay,Kanth, Priyanka,Mishra, Kirtika,Singh, Bachcha
, p. 116 - 128 (2017/03/08)
In this article, we report synthesis and characterization of a novel homologous series of butyl 4-(4′-(alkoxy)-2-hydroxybenzylideneamino)benzoates, CnLH (n = 6, 8, 10, 12, 14, 16) and their copper(II) complexes. The mesomorphic properties of th
Zinc(II)-salphen complexes bearing long alkoxy side arms: Synthesis, solvent dependent aggregation, and spacer group substituent effect on mesomorphism and photophysical property
Chakraborty, Sutapa,Mondal, Paritosh,Krishna Prasad,Shankar Rao,Bhattacharjee, Chira R.
, p. 290 - 301 (2017/09/29)
Hemi-disc shaped zinc(II) complexes of two new series of halogen-substituted ‘salphen’ type Schiff base ligands [ZnL]; H2L = [N,N′-Bis(4-n-alkoxysalicylidene)-4-fluoro/bromo-1,2-diaminobenzene] (n = 12, 14, 16) have been synthesized and their mesomorphism and photophysical properties investigated. The ligands and zinc(II) complexes displayed columnar mesophases over a much wider temperature range. Depending on the halogen substitution at the ligand's spacer; different variant of columnar phases were exhibited by the ligands and the zinc(II) complexes. The ligands and the complexes displayed fluorescence at ambient temperature in the blue-green region with moderate to low intensity. Density functional theory (DFT) calculations indicated a distorted square-planar geometry around the zinc(II) center in the complexes. The coordinative unsaturation of the zinc(II) center in these complexes leads to interesting aggregation properties in a dilute solution of non-coordinating solvents. However, in coordinating solvent, axial coordination to the zinc(II) ion occurred leading to complete de-aggregation to monomer.
Benzimidazole based mesogenic Schiff-bases: Synthesis and characterization
Dubey, Ragini,Yerrasani, Rajasekhar,Karunakar,Singh, Angad Kumar,Gupta, Rupali,Ganesan, Vellaichamy,Rao
, p. 106 - 114 (2017/05/25)
Two homologous series of mesogenic Schiff-bases, N-4-((alkoxy)-(phenyl-3-hydroxy-4-(4-(5-methylbenzimidazol))-2-alkoxysalicylaldimine)benzoate (7a–d) and N-4′-(5-methyl-benzimidazole)-phenyl-4-alkoxysalicylaldimine (8a–d) incorporating benzimidazole moiety have been prepared and the molecular structures studied by FT-IR, NMR and ESI-MS spectrometry. Mesogenic behaviour was investigated by polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and variable temperature powder X-ray diffraction (PXRD) techniques. Changing the spacer (ester-linked to non-ester linked) of the Schiff-base results in enhancement of thermal stability and phase transition temperature. The members of series-I show monotropic SmA while those of series-II reflect enantiotropic SmA mesomorphism. An electrochemical study of a representative Schiff base in each series (7d and 8c) showed an electrical band gap 1.26?eV and 1.22?eV respectively.
